FNB let people take money without you're permission

last month I had the same problem. Avis deducting money from my account without my permission. 3 transaction went off. After a month now all of a sudden again another transaction of 2472.44 guys come on my kids didn't even had money for bus last month because of this nonsense. Fnb told me block your card then they can't do anything. So I did now i have to block the card again and for what to pay for a new card again. Ha a guys.